Loading...
1/*
2 * raw.c - Raw sockets for protocol family CAN
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42#include <linux/module.h>
43#include <linux/init.h>
44#include <linux/uio.h>
45#include <linux/net.h>
46#include <linux/slab.h>
47#include <linux/netdevice.h>
48#include <linux/socket.h>
49#include <linux/if_arp.h>
50#include <linux/skbuff.h>
51#include <linux/can.h>
52#include <linux/can/core.h>
53#include <linux/can/raw.h>
54#include <net/sock.h>
55#include <net/net_namespace.h>
56
57#define CAN_RAW_VERSION CAN_VERSION
58static __initdata const char banner[] =
59 KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";
60
61MODULE_DESCRIPTION("PF_CAN raw protocol");
62MODULE_LICENSE("Dual BSD/GPL");
63MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
64MODULE_ALIAS("can-proto-1");
65
66#define MASK_ALL 0
67
68/*
69 * A raw socket has a list of can_filters attached to it, each receiving
70 * the CAN frames matching that filter. If the filter list is empty,
71 * no CAN frames will be received by the socket. The default after
72 * opening the socket, is to have one filter which receives all frames.
73 * The filter list is allocated dynamically with the exception of the
74 * list containing only one item. This common case is optimized by
75 * storing the single filter in dfilter, to avoid using dynamic memory.
76 */
77
78struct raw_sock {
79 struct sock sk;
80 int bound;
81 int ifindex;
82 struct notifier_block notifier;
83 int loopback;
84 int recv_own_msgs;
85 int count; /* number of active filters */
86 struct can_filter dfilter; /* default/single filter */
87 struct can_filter *filter; /* pointer to filter(s) */
88 can_err_mask_t err_mask;
89};
90
91/*
92 * Return pointer to store the extra msg flags for raw_recvmsg().
93 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
94 * in skb->cb.
95 */
96static inline unsigned int *raw_flags(struct sk_buff *skb)
97{
98 BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
99 sizeof(unsigned int)));
100
101 /* return pointer after struct sockaddr_can */
102 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
103}
104
105static inline struct raw_sock *raw_sk(const struct sock *sk)
106{
107 return (struct raw_sock *)sk;
108}
109
110static void raw_rcv(struct sk_buff *oskb, void *data)
111{
112 struct sock *sk = (struct sock *)data;
113 struct raw_sock *ro = raw_sk(sk);
114 struct sockaddr_can *addr;
115 struct sk_buff *skb;
116 unsigned int *pflags;
117
118 /* check the received tx sock reference */
119 if (!ro->recv_own_msgs && oskb->sk == sk)
120 return;
121
122 /* clone the given skb to be able to enqueue it into the rcv queue */
123 skb = skb_clone(oskb, GFP_ATOMIC);
124 if (!skb)
125 return;
126
127 /*
128 * Put the datagram to the queue so that raw_recvmsg() can
129 * get it from there. We need to pass the interface index to
130 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
131 * containing the interface index.
132 */
133
134 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
135 addr = (struct sockaddr_can *)skb->cb;
136 memset(addr, 0, sizeof(*addr));
137 addr->can_family = AF_CAN;
138 addr->can_ifindex = skb->dev->ifindex;
139
140 /* add CAN specific message flags for raw_recvmsg() */
141 pflags = raw_flags(skb);
142 *pflags = 0;
143 if (oskb->sk)
144 *pflags |= MSG_DONTROUTE;
145 if (oskb->sk == sk)
146 *pflags |= MSG_CONFIRM;
147
148 if (sock_queue_rcv_skb(sk, skb) < 0)
149 kfree_skb(skb);
150}
151
152static int raw_enable_filters(struct net_device *dev, struct sock *sk,
153 struct can_filter *filter, int count)
154{
155 int err = 0;
156 int i;
157
158 for (i = 0; i < count; i++) {
159 err = can_rx_register(dev, filter[i].can_id,
160 filter[i].can_mask,
161 raw_rcv, sk, "raw");
162 if (err) {
163 /* clean up successfully registered filters */
164 while (--i >= 0)
165 can_rx_unregister(dev, filter[i].can_id,
166 filter[i].can_mask,
167 raw_rcv, sk);
168 break;
169 }
170 }
171
172 return err;
173}
174
175static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
176 can_err_mask_t err_mask)
177{
178 int err = 0;
179
180 if (err_mask)
181 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
182 raw_rcv, sk, "raw");
183
184 return err;
185}
186
187static void raw_disable_filters(struct net_device *dev, struct sock *sk,
188 struct can_filter *filter, int count)
189{
190 int i;
191
192 for (i = 0; i < count; i++)
193 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
194 raw_rcv, sk);
195}
196
197static inline void raw_disable_errfilter(struct net_device *dev,
198 struct sock *sk,
199 can_err_mask_t err_mask)
200
201{
202 if (err_mask)
203 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
204 raw_rcv, sk);
205}
206
207static inline void raw_disable_allfilters(struct net_device *dev,
208 struct sock *sk)
209{
210 struct raw_sock *ro = raw_sk(sk);
211
212 raw_disable_filters(dev, sk, ro->filter, ro->count);
213 raw_disable_errfilter(dev, sk, ro->err_mask);
214}
215
216static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
217{
218 struct raw_sock *ro = raw_sk(sk);
219 int err;
220
221 err = raw_enable_filters(dev, sk, ro->filter, ro->count);
222 if (!err) {
223 err = raw_enable_errfilter(dev, sk, ro->err_mask);
224 if (err)
225 raw_disable_filters(dev, sk, ro->filter, ro->count);
226 }
227
228 return err;
229}
230
231static int raw_notifier(struct notifier_block *nb,
232 unsigned long msg, void *data)
233{
234 struct net_device *dev = (struct net_device *)data;
235 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
236 struct sock *sk = &ro->sk;
237
238 if (!net_eq(dev_net(dev), &init_net))
239 return NOTIFY_DONE;
240
241 if (dev->type != ARPHRD_CAN)
242 return NOTIFY_DONE;
243
244 if (ro->ifindex != dev->ifindex)
245 return NOTIFY_DONE;
246
247 switch (msg) {
248
249 case NETDEV_UNREGISTER:
250 lock_sock(sk);
251 /* remove current filters & unregister */
252 if (ro->bound)
253 raw_disable_allfilters(dev, sk);
254
255 if (ro->count > 1)
256 kfree(ro->filter);
257
258 ro->ifindex = 0;
259 ro->bound = 0;
260 ro->count = 0;
261 release_sock(sk);
262
263 sk->sk_err = ENODEV;
264 if (!sock_flag(sk, SOCK_DEAD))
265 sk->sk_error_report(sk);
266 break;
267
268 case NETDEV_DOWN:
269 sk->sk_err = ENETDOWN;
270 if (!sock_flag(sk, SOCK_DEAD))
271 sk->sk_error_report(sk);
272 break;
273 }
274
275 return NOTIFY_DONE;
276}
277
278static int raw_init(struct sock *sk)
279{
280 struct raw_sock *ro = raw_sk(sk);
281
282 ro->bound = 0;
283 ro->ifindex = 0;
284
285 /* set default filter to single entry dfilter */
286 ro->dfilter.can_id = 0;
287 ro->dfilter.can_mask = MASK_ALL;
288 ro->filter = &ro->dfilter;
289 ro->count = 1;
290
291 /* set default loopback behaviour */
292 ro->loopback = 1;
293 ro->recv_own_msgs = 0;
294
295 /* set notifier */
296 ro->notifier.notifier_call = raw_notifier;
297
298 register_netdevice_notifier(&ro->notifier);
299
300 return 0;
301}
302
303static int raw_release(struct socket *sock)
304{
305 struct sock *sk = sock->sk;
306 struct raw_sock *ro;
307
308 if (!sk)
309 return 0;
310
311 ro = raw_sk(sk);
312
313 unregister_netdevice_notifier(&ro->notifier);
314
315 lock_sock(sk);
316
317 /* remove current filters & unregister */
318 if (ro->bound) {
319 if (ro->ifindex) {
320 struct net_device *dev;
321
322 dev = dev_get_by_index(&init_net, ro->ifindex);
323 if (dev) {
324 raw_disable_allfilters(dev, sk);
325 dev_put(dev);
326 }
327 } else
328 raw_disable_allfilters(NULL, sk);
329 }
330
331 if (ro->count > 1)
332 kfree(ro->filter);
333
334 ro->ifindex = 0;
335 ro->bound = 0;
336 ro->count = 0;
337
338 sock_orphan(sk);
339 sock->sk = NULL;
340
341 release_sock(sk);
342 sock_put(sk);
343
344 return 0;
345}
346
347static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
348{
349 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
350 struct sock *sk = sock->sk;
351 struct raw_sock *ro = raw_sk(sk);
352 int ifindex;
353 int err = 0;
354 int notify_enetdown = 0;
355
356 if (len < sizeof(*addr))
357 return -EINVAL;
358
359 lock_sock(sk);
360
361 if (ro->bound && addr->can_ifindex == ro->ifindex)
362 goto out;
363
364 if (addr->can_ifindex) {
365 struct net_device *dev;
366
367 dev = dev_get_by_index(&init_net, addr->can_ifindex);
368 if (!dev) {
369 err = -ENODEV;
370 goto out;
371 }
372 if (dev->type != ARPHRD_CAN) {
373 dev_put(dev);
374 err = -ENODEV;
375 goto out;
376 }
377 if (!(dev->flags & IFF_UP))
378 notify_enetdown = 1;
379
380 ifindex = dev->ifindex;
381
382 /* filters set by default/setsockopt */
383 err = raw_enable_allfilters(dev, sk);
384 dev_put(dev);
385 } else {
386 ifindex = 0;
387
388 /* filters set by default/setsockopt */
389 err = raw_enable_allfilters(NULL, sk);
390 }
391
392 if (!err) {
393 if (ro->bound) {
394 /* unregister old filters */
395 if (ro->ifindex) {
396 struct net_device *dev;
397
398 dev = dev_get_by_index(&init_net, ro->ifindex);
399 if (dev) {
400 raw_disable_allfilters(dev, sk);
401 dev_put(dev);
402 }
403 } else
404 raw_disable_allfilters(NULL, sk);
405 }
406 ro->ifindex = ifindex;
407 ro->bound = 1;
408 }
409
410 out:
411 release_sock(sk);
412
413 if (notify_enetdown) {
414 sk->sk_err = ENETDOWN;
415 if (!sock_flag(sk, SOCK_DEAD))
416 sk->sk_error_report(sk);
417 }
418
419 return err;
420}
421
422static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
423 int *len, int peer)
424{
425 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
426 struct sock *sk = sock->sk;
427 struct raw_sock *ro = raw_sk(sk);
428
429 if (peer)
430 return -EOPNOTSUPP;
431
432 memset(addr, 0, sizeof(*addr));
433 addr->can_family = AF_CAN;
434 addr->can_ifindex = ro->ifindex;
435
436 *len = sizeof(*addr);
437
438 return 0;
439}
440
441static int raw_setsockopt(struct socket *sock, int level, int optname,
442 char __user *optval, unsigned int optlen)
443{
444 struct sock *sk = sock->sk;
445 struct raw_sock *ro = raw_sk(sk);
446 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
447 struct can_filter sfilter; /* single filter */
448 struct net_device *dev = NULL;
449 can_err_mask_t err_mask = 0;
450 int count = 0;
451 int err = 0;
452
453 if (level != SOL_CAN_RAW)
454 return -EINVAL;
455
456 switch (optname) {
457
458 case CAN_RAW_FILTER:
459 if (optlen % sizeof(struct can_filter) != 0)
460 return -EINVAL;
461
462 count = optlen / sizeof(struct can_filter);
463
464 if (count > 1) {
465 /* filter does not fit into dfilter => alloc space */
466 filter = memdup_user(optval, optlen);
467 if (IS_ERR(filter))
468 return PTR_ERR(filter);
469 } else if (count == 1) {
470 if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
471 return -EFAULT;
472 }
473
474 lock_sock(sk);
475
476 if (ro->bound && ro->ifindex)
477 dev = dev_get_by_index(&init_net, ro->ifindex);
478
479 if (ro->bound) {
480 /* (try to) register the new filters */
481 if (count == 1)
482 err = raw_enable_filters(dev, sk, &sfilter, 1);
483 else
484 err = raw_enable_filters(dev, sk, filter,
485 count);
486 if (err) {
487 if (count > 1)
488 kfree(filter);
489 goto out_fil;
490 }
491
492 /* remove old filter registrations */
493 raw_disable_filters(dev, sk, ro->filter, ro->count);
494 }
495
496 /* remove old filter space */
497 if (ro->count > 1)
498 kfree(ro->filter);
499
500 /* link new filters to the socket */
501 if (count == 1) {
502 /* copy filter data for single filter */
503 ro->dfilter = sfilter;
504 filter = &ro->dfilter;
505 }
506 ro->filter = filter;
507 ro->count = count;
508
509 out_fil:
510 if (dev)
511 dev_put(dev);
512
513 release_sock(sk);
514
515 break;
516
517 case CAN_RAW_ERR_FILTER:
518 if (optlen != sizeof(err_mask))
519 return -EINVAL;
520
521 if (copy_from_user(&err_mask, optval, optlen))
522 return -EFAULT;
523
524 err_mask &= CAN_ERR_MASK;
525
526 lock_sock(sk);
527
528 if (ro->bound && ro->ifindex)
529 dev = dev_get_by_index(&init_net, ro->ifindex);
530
531 /* remove current error mask */
532 if (ro->bound) {
533 /* (try to) register the new err_mask */
534 err = raw_enable_errfilter(dev, sk, err_mask);
535
536 if (err)
537 goto out_err;
538
539 /* remove old err_mask registration */
540 raw_disable_errfilter(dev, sk, ro->err_mask);
541 }
542
543 /* link new err_mask to the socket */
544 ro->err_mask = err_mask;
545
546 out_err:
547 if (dev)
548 dev_put(dev);
549
550 release_sock(sk);
551
552 break;
553
554 case CAN_RAW_LOOPBACK:
555 if (optlen != sizeof(ro->loopback))
556 return -EINVAL;
557
558 if (copy_from_user(&ro->loopback, optval, optlen))
559 return -EFAULT;
560
561 break;
562
563 case CAN_RAW_RECV_OWN_MSGS:
564 if (optlen != sizeof(ro->recv_own_msgs))
565 return -EINVAL;
566
567 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
568 return -EFAULT;
569
570 break;
571
572 default:
573 return -ENOPROTOOPT;
574 }
575 return err;
576}
577
578static int raw_getsockopt(struct socket *sock, int level, int optname,
579 char __user *optval, int __user *optlen)
580{
581 struct sock *sk = sock->sk;
582 struct raw_sock *ro = raw_sk(sk);
583 int len;
584 void *val;
585 int err = 0;
586
587 if (level != SOL_CAN_RAW)
588 return -EINVAL;
589 if (get_user(len, optlen))
590 return -EFAULT;
591 if (len < 0)
592 return -EINVAL;
593
594 switch (optname) {
595
596 case CAN_RAW_FILTER:
597 lock_sock(sk);
598 if (ro->count > 0) {
599 int fsize = ro->count * sizeof(struct can_filter);
600 if (len > fsize)
601 len = fsize;
602 if (copy_to_user(optval, ro->filter, len))
603 err = -EFAULT;
604 } else
605 len = 0;
606 release_sock(sk);
607
608 if (!err)
609 err = put_user(len, optlen);
610 return err;
611
612 case CAN_RAW_ERR_FILTER:
613 if (len > sizeof(can_err_mask_t))
614 len = sizeof(can_err_mask_t);
615 val = &ro->err_mask;
616 break;
617
618 case CAN_RAW_LOOPBACK:
619 if (len > sizeof(int))
620 len = sizeof(int);
621 val = &ro->loopback;
622 break;
623
624 case CAN_RAW_RECV_OWN_MSGS:
625 if (len > sizeof(int))
626 len = sizeof(int);
627 val = &ro->recv_own_msgs;
628 break;
629
630 default:
631 return -ENOPROTOOPT;
632 }
633
634 if (put_user(len, optlen))
635 return -EFAULT;
636 if (copy_to_user(optval, val, len))
637 return -EFAULT;
638 return 0;
639}
640
641static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
642 struct msghdr *msg, size_t size)
643{
644 struct sock *sk = sock->sk;
645 struct raw_sock *ro = raw_sk(sk);
646 struct sk_buff *skb;
647 struct net_device *dev;
648 int ifindex;
649 int err;
650
651 if (msg->msg_name) {
652 struct sockaddr_can *addr =
653 (struct sockaddr_can *)msg->msg_name;
654
655 if (msg->msg_namelen < sizeof(*addr))
656 return -EINVAL;
657
658 if (addr->can_family != AF_CAN)
659 return -EINVAL;
660
661 ifindex = addr->can_ifindex;
662 } else
663 ifindex = ro->ifindex;
664
665 if (size != sizeof(struct can_frame))
666 return -EINVAL;
667
668 dev = dev_get_by_index(&init_net, ifindex);
669 if (!dev)
670 return -ENXIO;
671
672 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
673 &err);
674 if (!skb)
675 goto put_dev;
676
677 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
678 if (err < 0)
679 goto free_skb;
680 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
681 if (err < 0)
682 goto free_skb;
683
684 skb->dev = dev;
685 skb->sk = sk;
686
687 err = can_send(skb, ro->loopback);
688
689 dev_put(dev);
690
691 if (err)
692 goto send_failed;
693
694 return size;
695
696free_skb:
697 kfree_skb(skb);
698put_dev:
699 dev_put(dev);
700send_failed:
701 return err;
702}
703
704static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
705 struct msghdr *msg, size_t size, int flags)
706{
707 struct sock *sk = sock->sk;
708 struct sk_buff *skb;
709 int err = 0;
710 int noblock;
711
712 noblock = flags & MSG_DONTWAIT;
713 flags &= ~MSG_DONTWAIT;
714
715 skb = skb_recv_datagram(sk, flags, noblock, &err);
716 if (!skb)
717 return err;
718
719 if (size < skb->len)
720 msg->msg_flags |= MSG_TRUNC;
721 else
722 size = skb->len;
723
724 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
725 if (err < 0) {
726 skb_free_datagram(sk, skb);
727 return err;
728 }
729
730 sock_recv_ts_and_drops(msg, sk, skb);
731
732 if (msg->msg_name) {
733 msg->msg_namelen = sizeof(struct sockaddr_can);
734 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
735 }
736
737 /* assign the flags that have been recorded in raw_rcv() */
738 msg->msg_flags |= *(raw_flags(skb));
739
740 skb_free_datagram(sk, skb);
741
742 return size;
743}
744
745static const struct proto_ops raw_ops = {
746 .family = PF_CAN,
747 .release = raw_release,
748 .bind = raw_bind,
749 .connect = sock_no_connect,
750 .socketpair = sock_no_socketpair,
751 .accept = sock_no_accept,
752 .getname = raw_getname,
753 .poll = datagram_poll,
754 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
755 .listen = sock_no_listen,
756 .shutdown = sock_no_shutdown,
757 .setsockopt = raw_setsockopt,
758 .getsockopt = raw_getsockopt,
759 .sendmsg = raw_sendmsg,
760 .recvmsg = raw_recvmsg,
761 .mmap = sock_no_mmap,
762 .sendpage = sock_no_sendpage,
763};
764
765static struct proto raw_proto __read_mostly = {
766 .name = "CAN_RAW",
767 .owner = THIS_MODULE,
768 .obj_size = sizeof(struct raw_sock),
769 .init = raw_init,
770};
771
772static const struct can_proto raw_can_proto = {
773 .type = SOCK_RAW,
774 .protocol = CAN_RAW,
775 .ops = &raw_ops,
776 .prot = &raw_proto,
777};
778
779static __init int raw_module_init(void)
780{
781 int err;
782
783 printk(banner);
784
785 err = can_proto_register(&raw_can_proto);
786 if (err < 0)
787 printk(KERN_ERR "can: registration of raw protocol failed\n");
788
789 return err;
790}
791
792static __exit void raw_module_exit(void)
793{
794 can_proto_unregister(&raw_can_proto);
795}
796
797module_init(raw_module_init);
798module_exit(raw_module_exit);
1/*
2 * raw.c - Raw sockets for protocol family CAN
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 * Send feedback to <socketcan-users@lists.berlios.de>
41 *
42 */
43
44#include <linux/module.h>
45#include <linux/init.h>
46#include <linux/uio.h>
47#include <linux/net.h>
48#include <linux/slab.h>
49#include <linux/netdevice.h>
50#include <linux/socket.h>
51#include <linux/if_arp.h>
52#include <linux/skbuff.h>
53#include <linux/can.h>
54#include <linux/can/core.h>
55#include <linux/can/raw.h>
56#include <net/sock.h>
57#include <net/net_namespace.h>
58
59#define CAN_RAW_VERSION CAN_VERSION
60static __initdata const char banner[] =
61 KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";
62
63MODULE_DESCRIPTION("PF_CAN raw protocol");
64MODULE_LICENSE("Dual BSD/GPL");
65MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
66MODULE_ALIAS("can-proto-1");
67
68#define MASK_ALL 0
69
70/*
71 * A raw socket has a list of can_filters attached to it, each receiving
72 * the CAN frames matching that filter. If the filter list is empty,
73 * no CAN frames will be received by the socket. The default after
74 * opening the socket, is to have one filter which receives all frames.
75 * The filter list is allocated dynamically with the exception of the
76 * list containing only one item. This common case is optimized by
77 * storing the single filter in dfilter, to avoid using dynamic memory.
78 */
79
80struct raw_sock {
81 struct sock sk;
82 int bound;
83 int ifindex;
84 struct notifier_block notifier;
85 int loopback;
86 int recv_own_msgs;
87 int count; /* number of active filters */
88 struct can_filter dfilter; /* default/single filter */
89 struct can_filter *filter; /* pointer to filter(s) */
90 can_err_mask_t err_mask;
91};
92
93/*
94 * Return pointer to store the extra msg flags for raw_recvmsg().
95 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
96 * in skb->cb.
97 */
98static inline unsigned int *raw_flags(struct sk_buff *skb)
99{
100 BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
101 sizeof(unsigned int)));
102
103 /* return pointer after struct sockaddr_can */
104 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
105}
106
107static inline struct raw_sock *raw_sk(const struct sock *sk)
108{
109 return (struct raw_sock *)sk;
110}
111
112static void raw_rcv(struct sk_buff *oskb, void *data)
113{
114 struct sock *sk = (struct sock *)data;
115 struct raw_sock *ro = raw_sk(sk);
116 struct sockaddr_can *addr;
117 struct sk_buff *skb;
118 unsigned int *pflags;
119
120 /* check the received tx sock reference */
121 if (!ro->recv_own_msgs && oskb->sk == sk)
122 return;
123
124 /* clone the given skb to be able to enqueue it into the rcv queue */
125 skb = skb_clone(oskb, GFP_ATOMIC);
126 if (!skb)
127 return;
128
129 /*
130 * Put the datagram to the queue so that raw_recvmsg() can
131 * get it from there. We need to pass the interface index to
132 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
133 * containing the interface index.
134 */
135
136 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
137 addr = (struct sockaddr_can *)skb->cb;
138 memset(addr, 0, sizeof(*addr));
139 addr->can_family = AF_CAN;
140 addr->can_ifindex = skb->dev->ifindex;
141
142 /* add CAN specific message flags for raw_recvmsg() */
143 pflags = raw_flags(skb);
144 *pflags = 0;
145 if (oskb->sk)
146 *pflags |= MSG_DONTROUTE;
147 if (oskb->sk == sk)
148 *pflags |= MSG_CONFIRM;
149
150 if (sock_queue_rcv_skb(sk, skb) < 0)
151 kfree_skb(skb);
152}
153
154static int raw_enable_filters(struct net_device *dev, struct sock *sk,
155 struct can_filter *filter, int count)
156{
157 int err = 0;
158 int i;
159
160 for (i = 0; i < count; i++) {
161 err = can_rx_register(dev, filter[i].can_id,
162 filter[i].can_mask,
163 raw_rcv, sk, "raw");
164 if (err) {
165 /* clean up successfully registered filters */
166 while (--i >= 0)
167 can_rx_unregister(dev, filter[i].can_id,
168 filter[i].can_mask,
169 raw_rcv, sk);
170 break;
171 }
172 }
173
174 return err;
175}
176
177static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
178 can_err_mask_t err_mask)
179{
180 int err = 0;
181
182 if (err_mask)
183 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
184 raw_rcv, sk, "raw");
185
186 return err;
187}
188
189static void raw_disable_filters(struct net_device *dev, struct sock *sk,
190 struct can_filter *filter, int count)
191{
192 int i;
193
194 for (i = 0; i < count; i++)
195 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
196 raw_rcv, sk);
197}
198
199static inline void raw_disable_errfilter(struct net_device *dev,
200 struct sock *sk,
201 can_err_mask_t err_mask)
202
203{
204 if (err_mask)
205 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
206 raw_rcv, sk);
207}
208
209static inline void raw_disable_allfilters(struct net_device *dev,
210 struct sock *sk)
211{
212 struct raw_sock *ro = raw_sk(sk);
213
214 raw_disable_filters(dev, sk, ro->filter, ro->count);
215 raw_disable_errfilter(dev, sk, ro->err_mask);
216}
217
218static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
219{
220 struct raw_sock *ro = raw_sk(sk);
221 int err;
222
223 err = raw_enable_filters(dev, sk, ro->filter, ro->count);
224 if (!err) {
225 err = raw_enable_errfilter(dev, sk, ro->err_mask);
226 if (err)
227 raw_disable_filters(dev, sk, ro->filter, ro->count);
228 }
229
230 return err;
231}
232
233static int raw_notifier(struct notifier_block *nb,
234 unsigned long msg, void *data)
235{
236 struct net_device *dev = (struct net_device *)data;
237 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
238 struct sock *sk = &ro->sk;
239
240 if (!net_eq(dev_net(dev), &init_net))
241 return NOTIFY_DONE;
242
243 if (dev->type != ARPHRD_CAN)
244 return NOTIFY_DONE;
245
246 if (ro->ifindex != dev->ifindex)
247 return NOTIFY_DONE;
248
249 switch (msg) {
250
251 case NETDEV_UNREGISTER:
252 lock_sock(sk);
253 /* remove current filters & unregister */
254 if (ro->bound)
255 raw_disable_allfilters(dev, sk);
256
257 if (ro->count > 1)
258 kfree(ro->filter);
259
260 ro->ifindex = 0;
261 ro->bound = 0;
262 ro->count = 0;
263 release_sock(sk);
264
265 sk->sk_err = ENODEV;
266 if (!sock_flag(sk, SOCK_DEAD))
267 sk->sk_error_report(sk);
268 break;
269
270 case NETDEV_DOWN:
271 sk->sk_err = ENETDOWN;
272 if (!sock_flag(sk, SOCK_DEAD))
273 sk->sk_error_report(sk);
274 break;
275 }
276
277 return NOTIFY_DONE;
278}
279
280static int raw_init(struct sock *sk)
281{
282 struct raw_sock *ro = raw_sk(sk);
283
284 ro->bound = 0;
285 ro->ifindex = 0;
286
287 /* set default filter to single entry dfilter */
288 ro->dfilter.can_id = 0;
289 ro->dfilter.can_mask = MASK_ALL;
290 ro->filter = &ro->dfilter;
291 ro->count = 1;
292
293 /* set default loopback behaviour */
294 ro->loopback = 1;
295 ro->recv_own_msgs = 0;
296
297 /* set notifier */
298 ro->notifier.notifier_call = raw_notifier;
299
300 register_netdevice_notifier(&ro->notifier);
301
302 return 0;
303}
304
305static int raw_release(struct socket *sock)
306{
307 struct sock *sk = sock->sk;
308 struct raw_sock *ro;
309
310 if (!sk)
311 return 0;
312
313 ro = raw_sk(sk);
314
315 unregister_netdevice_notifier(&ro->notifier);
316
317 lock_sock(sk);
318
319 /* remove current filters & unregister */
320 if (ro->bound) {
321 if (ro->ifindex) {
322 struct net_device *dev;
323
324 dev = dev_get_by_index(&init_net, ro->ifindex);
325 if (dev) {
326 raw_disable_allfilters(dev, sk);
327 dev_put(dev);
328 }
329 } else
330 raw_disable_allfilters(NULL, sk);
331 }
332
333 if (ro->count > 1)
334 kfree(ro->filter);
335
336 ro->ifindex = 0;
337 ro->bound = 0;
338 ro->count = 0;
339
340 sock_orphan(sk);
341 sock->sk = NULL;
342
343 release_sock(sk);
344 sock_put(sk);
345
346 return 0;
347}
348
349static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
350{
351 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
352 struct sock *sk = sock->sk;
353 struct raw_sock *ro = raw_sk(sk);
354 int ifindex;
355 int err = 0;
356 int notify_enetdown = 0;
357
358 if (len < sizeof(*addr))
359 return -EINVAL;
360
361 lock_sock(sk);
362
363 if (ro->bound && addr->can_ifindex == ro->ifindex)
364 goto out;
365
366 if (addr->can_ifindex) {
367 struct net_device *dev;
368
369 dev = dev_get_by_index(&init_net, addr->can_ifindex);
370 if (!dev) {
371 err = -ENODEV;
372 goto out;
373 }
374 if (dev->type != ARPHRD_CAN) {
375 dev_put(dev);
376 err = -ENODEV;
377 goto out;
378 }
379 if (!(dev->flags & IFF_UP))
380 notify_enetdown = 1;
381
382 ifindex = dev->ifindex;
383
384 /* filters set by default/setsockopt */
385 err = raw_enable_allfilters(dev, sk);
386 dev_put(dev);
387 } else {
388 ifindex = 0;
389
390 /* filters set by default/setsockopt */
391 err = raw_enable_allfilters(NULL, sk);
392 }
393
394 if (!err) {
395 if (ro->bound) {
396 /* unregister old filters */
397 if (ro->ifindex) {
398 struct net_device *dev;
399
400 dev = dev_get_by_index(&init_net, ro->ifindex);
401 if (dev) {
402 raw_disable_allfilters(dev, sk);
403 dev_put(dev);
404 }
405 } else
406 raw_disable_allfilters(NULL, sk);
407 }
408 ro->ifindex = ifindex;
409 ro->bound = 1;
410 }
411
412 out:
413 release_sock(sk);
414
415 if (notify_enetdown) {
416 sk->sk_err = ENETDOWN;
417 if (!sock_flag(sk, SOCK_DEAD))
418 sk->sk_error_report(sk);
419 }
420
421 return err;
422}
423
424static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
425 int *len, int peer)
426{
427 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
428 struct sock *sk = sock->sk;
429 struct raw_sock *ro = raw_sk(sk);
430
431 if (peer)
432 return -EOPNOTSUPP;
433
434 memset(addr, 0, sizeof(*addr));
435 addr->can_family = AF_CAN;
436 addr->can_ifindex = ro->ifindex;
437
438 *len = sizeof(*addr);
439
440 return 0;
441}
442
443static int raw_setsockopt(struct socket *sock, int level, int optname,
444 char __user *optval, unsigned int optlen)
445{
446 struct sock *sk = sock->sk;
447 struct raw_sock *ro = raw_sk(sk);
448 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
449 struct can_filter sfilter; /* single filter */
450 struct net_device *dev = NULL;
451 can_err_mask_t err_mask = 0;
452 int count = 0;
453 int err = 0;
454
455 if (level != SOL_CAN_RAW)
456 return -EINVAL;
457
458 switch (optname) {
459
460 case CAN_RAW_FILTER:
461 if (optlen % sizeof(struct can_filter) != 0)
462 return -EINVAL;
463
464 count = optlen / sizeof(struct can_filter);
465
466 if (count > 1) {
467 /* filter does not fit into dfilter => alloc space */
468 filter = memdup_user(optval, optlen);
469 if (IS_ERR(filter))
470 return PTR_ERR(filter);
471 } else if (count == 1) {
472 if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
473 return -EFAULT;
474 }
475
476 lock_sock(sk);
477
478 if (ro->bound && ro->ifindex)
479 dev = dev_get_by_index(&init_net, ro->ifindex);
480
481 if (ro->bound) {
482 /* (try to) register the new filters */
483 if (count == 1)
484 err = raw_enable_filters(dev, sk, &sfilter, 1);
485 else
486 err = raw_enable_filters(dev, sk, filter,
487 count);
488 if (err) {
489 if (count > 1)
490 kfree(filter);
491 goto out_fil;
492 }
493
494 /* remove old filter registrations */
495 raw_disable_filters(dev, sk, ro->filter, ro->count);
496 }
497
498 /* remove old filter space */
499 if (ro->count > 1)
500 kfree(ro->filter);
501
502 /* link new filters to the socket */
503 if (count == 1) {
504 /* copy filter data for single filter */
505 ro->dfilter = sfilter;
506 filter = &ro->dfilter;
507 }
508 ro->filter = filter;
509 ro->count = count;
510
511 out_fil:
512 if (dev)
513 dev_put(dev);
514
515 release_sock(sk);
516
517 break;
518
519 case CAN_RAW_ERR_FILTER:
520 if (optlen != sizeof(err_mask))
521 return -EINVAL;
522
523 if (copy_from_user(&err_mask, optval, optlen))
524 return -EFAULT;
525
526 err_mask &= CAN_ERR_MASK;
527
528 lock_sock(sk);
529
530 if (ro->bound && ro->ifindex)
531 dev = dev_get_by_index(&init_net, ro->ifindex);
532
533 /* remove current error mask */
534 if (ro->bound) {
535 /* (try to) register the new err_mask */
536 err = raw_enable_errfilter(dev, sk, err_mask);
537
538 if (err)
539 goto out_err;
540
541 /* remove old err_mask registration */
542 raw_disable_errfilter(dev, sk, ro->err_mask);
543 }
544
545 /* link new err_mask to the socket */
546 ro->err_mask = err_mask;
547
548 out_err:
549 if (dev)
550 dev_put(dev);
551
552 release_sock(sk);
553
554 break;
555
556 case CAN_RAW_LOOPBACK:
557 if (optlen != sizeof(ro->loopback))
558 return -EINVAL;
559
560 if (copy_from_user(&ro->loopback, optval, optlen))
561 return -EFAULT;
562
563 break;
564
565 case CAN_RAW_RECV_OWN_MSGS:
566 if (optlen != sizeof(ro->recv_own_msgs))
567 return -EINVAL;
568
569 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
570 return -EFAULT;
571
572 break;
573
574 default:
575 return -ENOPROTOOPT;
576 }
577 return err;
578}
579
580static int raw_getsockopt(struct socket *sock, int level, int optname,
581 char __user *optval, int __user *optlen)
582{
583 struct sock *sk = sock->sk;
584 struct raw_sock *ro = raw_sk(sk);
585 int len;
586 void *val;
587 int err = 0;
588
589 if (level != SOL_CAN_RAW)
590 return -EINVAL;
591 if (get_user(len, optlen))
592 return -EFAULT;
593 if (len < 0)
594 return -EINVAL;
595
596 switch (optname) {
597
598 case CAN_RAW_FILTER:
599 lock_sock(sk);
600 if (ro->count > 0) {
601 int fsize = ro->count * sizeof(struct can_filter);
602 if (len > fsize)
603 len = fsize;
604 if (copy_to_user(optval, ro->filter, len))
605 err = -EFAULT;
606 } else
607 len = 0;
608 release_sock(sk);
609
610 if (!err)
611 err = put_user(len, optlen);
612 return err;
613
614 case CAN_RAW_ERR_FILTER:
615 if (len > sizeof(can_err_mask_t))
616 len = sizeof(can_err_mask_t);
617 val = &ro->err_mask;
618 break;
619
620 case CAN_RAW_LOOPBACK:
621 if (len > sizeof(int))
622 len = sizeof(int);
623 val = &ro->loopback;
624 break;
625
626 case CAN_RAW_RECV_OWN_MSGS:
627 if (len > sizeof(int))
628 len = sizeof(int);
629 val = &ro->recv_own_msgs;
630 break;
631
632 default:
633 return -ENOPROTOOPT;
634 }
635
636 if (put_user(len, optlen))
637 return -EFAULT;
638 if (copy_to_user(optval, val, len))
639 return -EFAULT;
640 return 0;
641}
642
643static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
644 struct msghdr *msg, size_t size)
645{
646 struct sock *sk = sock->sk;
647 struct raw_sock *ro = raw_sk(sk);
648 struct sk_buff *skb;
649 struct net_device *dev;
650 int ifindex;
651 int err;
652
653 if (msg->msg_name) {
654 struct sockaddr_can *addr =
655 (struct sockaddr_can *)msg->msg_name;
656
657 if (msg->msg_namelen < sizeof(*addr))
658 return -EINVAL;
659
660 if (addr->can_family != AF_CAN)
661 return -EINVAL;
662
663 ifindex = addr->can_ifindex;
664 } else
665 ifindex = ro->ifindex;
666
667 if (size != sizeof(struct can_frame))
668 return -EINVAL;
669
670 dev = dev_get_by_index(&init_net, ifindex);
671 if (!dev)
672 return -ENXIO;
673
674 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
675 &err);
676 if (!skb)
677 goto put_dev;
678
679 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
680 if (err < 0)
681 goto free_skb;
682 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
683 if (err < 0)
684 goto free_skb;
685
686 /* to be able to check the received tx sock reference in raw_rcv() */
687 skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF;
688
689 skb->dev = dev;
690 skb->sk = sk;
691
692 err = can_send(skb, ro->loopback);
693
694 dev_put(dev);
695
696 if (err)
697 goto send_failed;
698
699 return size;
700
701free_skb:
702 kfree_skb(skb);
703put_dev:
704 dev_put(dev);
705send_failed:
706 return err;
707}
708
709static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
710 struct msghdr *msg, size_t size, int flags)
711{
712 struct sock *sk = sock->sk;
713 struct sk_buff *skb;
714 int err = 0;
715 int noblock;
716
717 noblock = flags & MSG_DONTWAIT;
718 flags &= ~MSG_DONTWAIT;
719
720 skb = skb_recv_datagram(sk, flags, noblock, &err);
721 if (!skb)
722 return err;
723
724 if (size < skb->len)
725 msg->msg_flags |= MSG_TRUNC;
726 else
727 size = skb->len;
728
729 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
730 if (err < 0) {
731 skb_free_datagram(sk, skb);
732 return err;
733 }
734
735 sock_recv_ts_and_drops(msg, sk, skb);
736
737 if (msg->msg_name) {
738 msg->msg_namelen = sizeof(struct sockaddr_can);
739 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
740 }
741
742 /* assign the flags that have been recorded in raw_rcv() */
743 msg->msg_flags |= *(raw_flags(skb));
744
745 skb_free_datagram(sk, skb);
746
747 return size;
748}
749
750static const struct proto_ops raw_ops = {
751 .family = PF_CAN,
752 .release = raw_release,
753 .bind = raw_bind,
754 .connect = sock_no_connect,
755 .socketpair = sock_no_socketpair,
756 .accept = sock_no_accept,
757 .getname = raw_getname,
758 .poll = datagram_poll,
759 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
760 .listen = sock_no_listen,
761 .shutdown = sock_no_shutdown,
762 .setsockopt = raw_setsockopt,
763 .getsockopt = raw_getsockopt,
764 .sendmsg = raw_sendmsg,
765 .recvmsg = raw_recvmsg,
766 .mmap = sock_no_mmap,
767 .sendpage = sock_no_sendpage,
768};
769
770static struct proto raw_proto __read_mostly = {
771 .name = "CAN_RAW",
772 .owner = THIS_MODULE,
773 .obj_size = sizeof(struct raw_sock),
774 .init = raw_init,
775};
776
777static const struct can_proto raw_can_proto = {
778 .type = SOCK_RAW,
779 .protocol = CAN_RAW,
780 .ops = &raw_ops,
781 .prot = &raw_proto,
782};
783
784static __init int raw_module_init(void)
785{
786 int err;
787
788 printk(banner);
789
790 err = can_proto_register(&raw_can_proto);
791 if (err < 0)
792 printk(KERN_ERR "can: registration of raw protocol failed\n");
793
794 return err;
795}
796
797static __exit void raw_module_exit(void)
798{
799 can_proto_unregister(&raw_can_proto);
800}
801
802module_init(raw_module_init);
803module_exit(raw_module_exit);